When issued with no arguments, the command asadmin start-domain fails with the error:
CLI143 There is more than one domain in C:\\Sun\\AppServer\\domains. Please use operand to specify the domain. CLI156 Could not start the domain null.
This error occurs when there is more than one domain in the domains directory, none of them is named domain1, and no domain is specified with the start-domain command.
Specify the domain when issuing the start-domain command:
asadmin start-domain domain1